A novel gel-based method for self-collection and ambient temperature postal transport of urine for PCR detection of Chlamydia trachomatis

• Published in: Sexually transmitted infections Vol. 85; no. 2; p. 102
• Main Authors: Bialasiewicz, S, Whiley, D M, Buhrer-Skinner, M, Bautista, C, Barker, K, Aitken, S, Gordon, R, Muller, R, Lambert, S B, Debattista, J, Nissen, M D, Sloots, T P
• Format: Journal Article
• Language: English
• Published: England 01-04-2009
• Subjects: Chlamydia Infections - diagnosis; Chlamydia Infections - urine; Chlamydia trachomatis - isolation & purification; DNA, Bacterial - urine; Female; Gels; Humans; Male; Polymerase Chain Reaction; Prospective Studies; Reagent Kits, Diagnostic - standards; Sensitivity and Specificity; Specimen Handling - methods
• ISSN: 1472-3263
• DOI: 10.1136/sti.2008.032607

The aim of this study was to develop a novel urine transport method to be used in self-collection-based screening for Chlamydia trachomatis. The method needed to be suitable for C trachomatis PCR detection, be economical and suitable for transport by standard envelope mailing.
An anhydrous gel composed of super-absorbent polymer and buffering agent was used to desiccate urine into a dry granulous state, which could subsequently be reconstituted upon arrival at a laboratory. DNA was then extracted from the reconstituted solution using the Roche MagNA Pure protocol for the detection of C trachomatis by PCR. Collections of urine specimens from three populations with widely differing chlamydia prevalence (100%,n = 56; 47%, n = 70; 3%, n = 97) were used. We determined the gel method's impact on C trachomatis PCR sensitivity and specificity using neat and gel-processed urine specimens. An equine herpes virus PCR was used to test for assay inhibition.
Overall, the sensitivity of the gel-based method ranged from 94.6-100% compared with neat urine, with a specificity of 100%. No PCR inhibition or decrease in analytical sensitivity was observed using the gel-processed extracts.
The gel-based method was found to be suitable for the detection of C trachomatis by PCR. In addition, its ease of use, effectiveness at ambient temperature and low cost makes it well-suited for self-collection kits used in population-based C trachomatis screening, particularly for geographically and socially isolated individuals.